Try to export as json, blender throws this error: AttributeErrpr: 'Image' object has no attribute 'file_path_from_user'
You need to update your version of blender. The image.filepath_from_user() was added to blender in 2.70 and you are using 2.69

This answer appears to include an up to date source for blender.

If you are using steam you can also install blender from there.